1. Field of the Invention
Embodiments of the present invention generally relate to an imaging system and, more particularly, the present invention relates to wide area terrain mapping.
2. Description of the Related Art
The geographic system industry has begun to exploit scanning LIDAR (Light Detection and Ranging) techniques to directly collect three-dimensional topography. Typically, a single laser beam is moved over the ground using aircraft motion and scanning mirrors. Using a measure of the time of flight for each pulse of a laser, range from the laser to the ground (or objects thereon) is estimated. Range samples are transformed to three-dimensional points in ground coordinates using high accuracy, onboard GPS/INS data and scan angles (collectively, “metadata”). The points are then connected into a three-dimensional mesh surface or re-gridded to a uniformly sampled digital elevation map (DEM) for display to a user. However, commercial scanning LIDAR instruments are relatively expensive and bulky such that aerial imagery (video imagery) must be acquired separately and then “draped” over the three-dimensional terrain that has been produced by the LIDAR technique. Such a process is costly, labor intensive, and time consuming.
Therefore, there is a need in the art for a comprehensive wide area terrain mapping system that combines both LIDAR information and electro-optic information, e.g., video images, in a single platform.